My friend who I met while studying abroad is coming to the states. A girl in the same study abroad program isalso friends with her but we weren't good friends, she's ditzy and has said incredibly ignorant things that I don't like (ex: a different friend was at a club with a black guy and we couldn't find her for a bit and this girl was like oh are we worried because she's with a big scary black guy?) and is just like annoying. Wants to stay in my apt now because we both want to see our friend. But I really don't want her to stay with me. I don't feel like cleaning, and like I know she wouldn't extend the same courtesy to me. How do I tell her no? I already hinted that my apt is tiny and I would have to find her an air mattress